Automatic container filling apparatus



Sept. 8, 1970 A. MooRE 3,527,267

AUTOMATIC CONTAINER FILLING APPARATUS Fild 0G13. 1'?, 1967 5 Sheets-Sheet l NUK-N .j INVENTR ,4l/fredv 'Moore ATTORNEY` 3 Sheets-Sheet 2 AIR INVENTOR ATTORNEYS A. MOORE AUTOMATIC CONTAINER FILLING APPARATUS /I/////If{/// Filed Oct. 17, 1967 sept. s, 1970 Sept. 8, 1970 A. MOORE 3,527,267

AUTOMATIC CONTAINER FILLING APPARATUS Filed Oct. 17, 1967 3 Sheets-Sheet 3 l ||5 4:* H9 ||O0\ H7) v TO SENSING TUBE INVENTOR A/fred Moore ATTORNEYS United States Patent O Int. Cl. B67d 5/372 U.S. Ci. 14l--40 16 Claims ABSTRACT F THE DISCLOSURE An automatic machine for filling continuously a moving row of containers with a fluent product comprises a filling head for each container having a product fill nozzle adapted to extend into the container during filling and adapted to be withdrawn after filling. The type of filling head with which the invention is concerned incorporates a low pressure air sensing tube within the nozzle, and when the product in the container reaches and blocks the lower end of the sensing tube to raise the pressure in the sensing tube a control device is actuated to shut off the product fill valve leading to the nozzle. The term low pressure air includes vacuum. The rise in pressure in the sensing tube when the lower end is blocked is relatively rapid and this rapid pressure or pulse is applied directly to one side of a primary exible diaphragm in the control device which at the other side is adapted to produce a corresponding amplified pressure rise or pulse in a high pressure air control circuit, preferably by selective throttling of an open end of a conduit in the high pressure air control circuit. This pulse is in turn applied to control a pressure responsive device in a high pressure air operating circuit for the product fill valve.

The invention discloses two specific modes of isolating the effect of a gradual rise or other change in a set low pressure air level in the sensing tube, such as may .be caused by product gradually restricting the tube opening over a period of time, to prevent premature shut off of the product fill control valve. In one embodiment, an intermediate pressure compensation chamber is provided between the primary diaphragm and a second flexible diaphragm that throttles the high pressure air conduit, and this intermediate chamber is restrictively vented to atmosphere so that a gradual rise in pressure at the one side of the primary diaphragm will not move or affect the throttling action of the second diaphragm, while a rapid rise or pulse will be transmitted to quickly operate the second diaphragm and effect ll valve shut off.

In the other embodiment the compensation for a gradual rise in air pressure in the sensing tube is accomplished in the high pressure air control circuit. Here the primary diaphragm directly throttles the conduit in the high pressure air control circuit and the high pressure air at the other side of the diaphragm is applied to opposite sides of a diaphragm assembly connected to control the high pressure air fill valve control circuit. A restriction is provided in the passage connecting the opposite sides of this diaphragm assembly. Thus a gradual rise in air pressure in the sensing tube Will proportionately appear in the high pressure air control circuit, but it will not move or otherwise affect the diaphragm assembly, while a rapid rise or pulse will, due to the aforesaid restriction in the high pressure air passage, unequally apply the pulse to opposite sides of the diaphragm assembly and actuate the product lill valve.

3,527,267 Patented Sept. 8, 1970 ICC BACKGROUND AND SUMMARY OF INVENTION Automatic container illing machines are known wherein a sensing tube containing low pressure air or vacuum and connected to a control device extends through the till nozzle of a product liquid lling head and wherein blocking if the lower end of the sensing tube as the container reaches a desired lill level actuates the control device to close the product -fill valve.

It has lbeen found that many highly viscous or sticky liquids tend to coat and harden in layers within the lower end of the sensing tube and are not removed even by an air blast synchronized with removal of the tube from the container. These coatings dry and otherwise accumulate on the sensing tube inner surfaces to eventually gradually reduce the effective inside diameter of the sensing tube. Any reduction in inner diameter of the sensing tube results in a pressure increase in the low pressure air upstream, and this results in premature actuation of the control device to shut off the product fill valve before the container is properly filled, and the invention is directed to solve this problem of premature shut off due to this or any other cause.

The invention solves this problem by providing a compensating arrangement associated with the control device whereby gradual pressure rise in the low pressure air of the sensing tube is ineffective on the control action, while a sharp rise or pulse in the pressure in the sensing tube effects the desired product fill valve cut off, and this is the major object of the present invention.

It is another object of the invention to provide a novel arrangement for amplifying a low pressure pulse caused by product blocking the lower end of a sensing tube in a wherein automatic compensation is provided for insuring filled container and applying the amplified pulse to effect a substantially uniform time shut off of a product fill valve after said pulse starts, regardless of gradual small changes in pressure in the sensing tube.

A further object of the invention is to provide in a system wherein a rapid rise in low pressure air in a product ll sensing tube is effective through a pressure responsive control device to provide a related rapid rise in a high pressure air control circuit containing a pressure responsive device for triggering actuation of a valve in a product iill valve circuit, means for automatically compensating for an undesired gradual increase in pressure within the sensing tube in such manner that the pressure pulse in the high pressure air control circuit always has a substantially uniform time constant shut olf with respect to a controlled threshold value. In one embodiment the compensating means is interposed between the low pressure region at the sensing tube and the high pressure of the control circuit, and in another embodiment the compensation is applied to the pressure responsive device in the high pressure control circuit.

Further objects will appear with respect to details and mode of operation as explained in the specification and recited in the claims.

As a result of the invention, the entire automatic tilling operation is improved, and the machine operates over longer periods with little maintenance and no shutdown time for cleaning restricted sensing tubes. This is a great saving in rejects because restriction of the sensing tube is usually gradual and often many improperly filled containers pass out of the machine and must be rejected before the improper automatic operation is discovered. The invention avoids such waste.

3 BRIEF DESCRIPTION OF DRAWINGS pensation arrangement for the system of FIGS. 1-3;

FIG. 5 is a sectional view showing a physical embodiment of the modification of FIG. 4 for incorporation into the apparatus shown in FIGS. 1 3; and

FIG. 6 is a section on line 6 6 of FIG. 5 showing the weight guide detail.

PREFERED EMBODIMENTS Referring to FIG. l, containers 11 arriving on a belt conveyor 12 are transferred by starwheel 13 in accurately spaced relation onto the continuously rotating table 14 of a filling machine assembly. The containers 11, which may be plastic bottles as illustrated in FIG. 2, are filled with a product liquid such as a liquid detergent as they are carried around on the conveyor. A second starwheel 15 removes the filled containers from table 14 and delivers them to take-away conveyor 16.

Rotating with table 14 are a series of container filling heads 17 one for each container being filled and one of which is shown in FIG. 2. These heads are engaged in filling relation with the containers during travel between stations S1 and S2 shown in FIG. l.

Except for certain structural details and sequential operational steps the filling heads and their mounting, arrangement and actuation in the filling assembly are known and need not be described in detail, as will appear.

One filling head 17 is shown in FIG. 2, and it comprises a body member 18 having an internal downwardly open bore 19 formed with a downwardly diverging smooth circular valve seat 21. A hollow lower body member 22 is detachably secured, as by screw threaded connection 23, to member 18 just below valve seat 21. Member 22 has a smaller diameter opening Z4 in its lower end in which is fixed a fill nozzle tube 25.

One side of bore 19 is formed with an opening 26 in which is fixed a tube 27 receiving the end of a conduit 28 from a supply of liquid product indicated at 29.

Above bore 19, a body member 18 is formed with a smaller bore 31 in which is vertically slidably mounted the hollow stem 32 of a product flow control valve 33. An annular conical face 34 is formed on the upper part of valve 33, adapted to engage seat 21 in the valve closed position of FIG. 3. An O-ring or like resilient seal 35 is preferably mounted in a groove 36 in valve face 34 to insure good sealing closure at the valve. Thus flow of the product liquid from the supply to the container is controlled by the position of valve 33.

A resilient O-ring seal 37 is mounted in a groove 38 at the upper end of bore 31, and seal 37 is compressed by a hollow thimble 39 threaded into the top of body member 18 so as to provide a liquid tight seal around stern 32 without interferring with the sliding displacement of the valve stem.

Thimble 39 also serve as a guide for a surrounding coil spring 41 that is compressed between the top surface 42 of body member 18 and a washer 43 on stem 32 which is anchored against upward vertical displacement along the stem by a snap ring and groove arrangement at 44. Spring 41 biases valve 33 toward its FIG. 3 closed position.

Valve stem 32 has a control lbore 45 closed at the upper end by end wall 46 on which is fixed a rigid post 47. Bore 45 is formed with side opening 48 mounting a nipple 49 connected to a conduit 51 adapted to deliver into bore 45 either low pressure (about seven inches of water) air from a source 50 or high pressure (about 60 pounds per square inch) from a source 52 as will appear. Source 50 may even in some cases be subatmospheric, so that the term low pressure air includes a vacuum. The lower end of bore 45 is threaded at 53 within valve 33 to mount a hollow sleeve 54 which has fixed thereto a depending sensing tube 55 of smaller diameter than and concentric with nozzle tube 25. When sleeve 54 is drawn tight an O-ring seal 56 is compressed to insure against fluid leading through the threads 53. Tube 55 is open at both ends and provides an effective continuation of stem bore 45.

Post 47 on valve stem 32 abuts the end of a rod 57 fixed to a piston 58 slidable in a cylinder 59 open at its upper end to receive a conduit 61 for delivering air under pressure to chamber 62. A compression spring 63 biases piston 58 upwardly in chamber 62.

A shuttle type air valve assembly 64 comprises a housing 65 that contains an internal chamber 66 within which a shuttle element 67 may assume either of two operational positions, one as shown in FIG. 2 and the other as shown in FIG. 3. In the product fill valve open condition of the apparatus shown in FIG. 2, which is the condition prevailing when a container 11 on table 14 is moving clockwise and is being filled with liquid from supply conduit 28, shuttle element 67 is disposed to the right in chamber 66 to establish a path for high pressure air from a high pressure air fill valve circuit conduit 68 leading from source 52 through shuttle valve inlet 69, passage 71 having orifices 71 at its opposite ends, and passage 72 in the shuttle element 67, outlet passage 73 and conduit 61 to cylinder chamber 62 wherein the pressure urges piston 58 down to compress spring 63 and to displace stem 32 downwardly and open valve 33. Orifices 71 insure displacement of the shuttle element during the operation hereinafter described.

Referring to FIG. 3, which shows the lower end of the filling head nozzle 25 enlarged, tube 55 extends into a cup-shaped cylindrical shell 81 that has a sliding t with the internal surface 82 of nozzle tube 25. The bottom 83 of shell 81 is closed except for opening 84 where the open lower end of tube 55 terminates. Shell 81 is fixed on tube 55. A series of openings 85 are provided in the side wall of shell 81, so that when valve 33 has been displaced to its open position of FIG. 2 the product liquid descending nozzle tube 25 around the outer periphery of tube 55 will be diverted laterally outwardly toward the adjacent upper container walls to reduce foaming during filling.

As each empty container 11 maintained on table 14 by conventional means (not shown) and having an individual filling head 17 disposed in association with its nozzle tube 25 thrust into the container neck approaches the station S1 indicated in FIG. 1, valve 33 is in the closed position shown in FIG. 3 and the shuttle valve element 67 is at the left side of the chamber 66I as also shown in FIG.v 3. The arrangement for inserting nozzle 25 into the container 11 to the distance shown in FIG. 2 is conventional and need not be described.

At station S1 (FIGS. 1 and 2`) the roller 101 of a switching device 102 moving with the table 14, there being one at or on each filling head 17, engages a cam projection 103 on stationary track 104. A high pressure air line 105 from source 52 contains a valve 106 operated by switching device 102 and, just before cam roller 101 engages cam 103, valve 106 is open to pass high pressure air through line 105 to maintain shuttle 67 in its left (FIG. 3) position in chamber 66.

When roller 101 passes over cam 103, switching device 102 is actuated momentarily to move valve 106 to the closed condition indicated in dotted lines in FIG. 2' to connect line 105 to exhaust to atmosphere. Valve 106 reopens after roller 101 passes cam 103, but during the short period it was closed, the lowered pressure in the right side of chamber 66 permits the opposing high pressure applied through line 68 and inlet 69 to quickly shift shuttle 67 from its FIG. 3 position to wits FIG. 2 position where it is maintained by the high pressure air in chamber 66 acting on both ends of the shuttle 67 when valve 106 reopens.

With shuttle 67 now" in the FIG. 2 position, high pressure air is applied through conduit 68, inlet 69, passages 71, 72 and 73 and conduit 61 to cylinden chamber 62 to displace piston S, wherebyrstem 32 is depressed to open lill valve 33 and start owtof the product liquid into container 11.

At this time the shell 81 is displaced to the FIG. 2 position below the end edge of nozzle tube touncover discharge openings 85 and directfthe product liquid into the container. This condition continues until the container is properly lled and has reached the region of station S2 of FIG. l, and at this ,time the container and till head are separated by conventional means (not shown) so that the lled container can be taken olf table 14.

As the filling container approaches station S2, the rising level of liquid therein eventually approaches the open lower end of sensing tube 55.

With reference to FIG. 2, lill control means in the form of a pneumatic amplier device 108 comprises a housing 109 divided by two spaced parallel internal ilexible diaphragms 110 and 111 into a low pressure air chamber 112, an intermediate chamber 114 and a regulator chamber 113. Low pressure air from source 50 passes through conduit 115 to a valve 116 for connecting it to conduit 51 and sensing tube 55 from which it discharges into the container and may escape through the space between nozzle 25 and the container neck. This low pressure air is also supplied by branch conduit 117 into low pressure chamber 112 where it tends to bias primary diaphragm 110 to the left. Intermediate chamber 114 is vented to atmosphere through a suitably restricted housing orice 118. Conduit 115 has a iixed restriction 115 located upstream of branch conduit 117.

High pressure air from source 52 passes through a high air pressure control circuit conduit 119` into a conduit 120 that has an open end 121 disposed within chamber 113 adjacent diaphragm 111. High pressure air discharged into chamber 113 urges diaphragm 111 to the right in FIG. 2 to tend to reduce its throttling action on the end of conduit 120, and its exhausts from chamber 113 through openings 122. `Conduit 119 has a lixed restriction 119' upstream of the juncture with conduit 120.

The force exerted by the high pressure air acting on one side of diaphragm 111 urging that diaphragm away from the open end of conduit 120 isopposite to the force exerted by the low pressure air of chamber 112 transmitted through diaphragm 110 and chamber 114 to act on the other side of diaphragm 111 to urge it toward the open end of conduit 120. In practice relative air pressures and physical features are so arranged and correlated that a balanced throttling action is exerted by diaphragm 111 on the high pressure air ow through chamber 113 to produce a desired amplier threshold pressure in conduit 120. The pressure in conduit 120 may be identified as the amplified sensing pressure. This action and the novel function of chamber 114 in the association will be further described in more detail.

High pressure air is also connected by line 120` to a cylinder chamber 124 for acting on a piston 125 in a direction opposite to a compression spring 126. The stem 127 of piston 125 is connected to a valve element 128 seating on an outlet or discharge aperture 129 in casing 130. Normally the force of spring 126 is high enough to overcome the amplied sensing pressure in chamber 12.4 and hold valve element 128 in closed position over aperture 129.

An inlet 131 in housing 130` is connected by conduit 132 to an opening 133 into shuttle valve chamber 66, and

to the valve 134 of a switching device S2 that is normally in the closed dotted line condition shown in FIG. 2. During container lling it will be seen therefore that high pressure air from shuttle valve chamber -66 is connected into valve casing 130 where exhaust is prevented by the closed valve 128.

When the rising liquid in container 11 has reached and blocked the lower end of sensing tube 55, pressure will rapidly increase in tube S5 and chamber 112, this resulting in diaphragm being displaced to the left in FIG. 2 and this force is transmitted through chamber 114 to displace diaphragm 111 to the left to further throttle conduit opening 121. As a result, air pressure now increases rapidly in chamber 113 and within conduit 120 and this increased air pressure pulse is effective to increase the amplied sensing pressure in cylinder chamber 124 and raise piston 125 until valve element 128` is unseated from outlet 129, thereby quickly connecting the left end of chamber 66 to exhaust at aperture 129. At this point, the higher air pressure from line 105 will quickly shift shuttle 67 to the left to its FIG. 3 position wherein line 61 is connected to exhaust through passages 73, 136 and 137. Spring 63 now acts to quickly close valve 33, and this stops the filling of container 11. The pressure in chamber 124 reduces when the end of tube 55 raises out of the liquid.

At station S2 a safety arrangement may be provded to shut off valve 33. This comprises the normally closed valve 138 which when roller 139 passes over cam 141 is momentarily opened to exhaust line 132 and permit the shuttle valve to assume its FIG. 3 position.

After passing station S2, lling head 17 on the moving table is disposed as in FIG. 3 with shell 81 drawn up into nozzle 25. A further switching device 142 moving around with and usually on the filling head is mechanically connected -by line 143 to valve 116, and when cam roller 144 passes over cam 145, valve 116 is turned to disconnect conduit 51 from the loW pressure air line 115 and c011- nect conduit 51 for a short period to the high pressure air line 144. This delivers a blast of high pressure air down sensing tube 55 for blowing out any residue or coating of the product liquid that may remain on the surface 95.

The foregoing construction and arrangements are merely conventional except for the structure and operation of the compensation arrangements associated with control device 108 and their cooperative association with the rest of the apparatus to improve the efficiency of container lilling control.

Prior to the invention a control device was provided at this area at 108 wherein the low pressure sensing air was applied directly to the opposite side of a throttling dia phragm for the high pressure air. This type of operation may be `adequate while the supplied low pressure in the line remains constant and/or while the sensing tube 55 is clean and free of restrictions. However, during operation and particularly with certain type of products being iilled into the container, the lower internal diameter of tube 55 may become restricted due to the accumulation of product which hardens in layers around surface 95. This restriction of tube 55 results in an increase of the present threshold level of low air pressure within tube 55 which is directly effective on the throttling diaphragm to raise the threshold high pressure level in the conduit leading to cylinder chamber 124 of FIG. 2, with the disadvantage that when the rising liquid in the container starts quickly blocking the lower end of sensing tube 55 the shut off actuating pressure within chamber 124 rises more quickly to the eiective high pressure value which actuates the shuttle valve to cut olf the flow of product. This results in only partial filling of the containers, and since it is usually some time before this fact is discovered in a high speed automatic machine considerable waste results.

The foregoing disadvantages are eliminated in the present invention wherein the intermediate chamber 114 serves essentially as a dashpot or damping arrangement whereby gradual or slow pressure increases in the low pressure chamber 112 do not noticeably affect the high pressure level in chamber 113. As the low pressure air in chamber 112 increases, as when the lower end of sensing tube 55 become restricted, the increased pressure in chamber 112 will result in leftward displacement of diaphragm 110 but since chamber 114 is vented to atmosphere air will be correspondingly displaced out of restricted orifice 118 and there will be no effective increase in the force acting to displace diaphragm 111 to the left in FIG. 2. When the rising liquid blocks the lower end of sensing tube 55, the resultant rapid increase in pressure the chamber 112 is transmitted as a pulse through chamber 114 since orifice 118 restricts outflow of air, and so this pulse exerts a force on diaphragm 111 displacing it toward the open end of conduit 120 and producing the rapid rise in high air pressure in conduit 120 that results in triggering of the shuttle valve to cutoff product flow.

It has been found that the foregoing action is effective even when the lower end of the sensing tube is almost closed by accumulated solid product to provide uniform desired filling of the containers.

The actuating pressure existing in conduit 120 during filling is not affected by gradual change or drift in the sensing pressure and therefore the cylinder 1'24 may be so arranged that the critical air pressure for displacing piston 125 to trigger shuttle valve operation may be set closer to the threshold high air pressure in conduit 120 for more rapid cut-off. This helps to speed up the entire automatic machine.

FIGS. 4-6 illustrate another embodiment of the invention wherein compensation control is exercised according to the rate of change in the amplified sensing pressure in high pressure air conduit 120. Certain parts corresponding to like parts in FIG. l bear the same number with the subscript a in FIG. 4.

Referring to FIG. 4 which shows this part of the overall FIG. 1 system diagrammatically, an abrupt change in pressure in the low pressure air conduit 115 which is connected to sensing tube 55 as in FIG. 1 displaces primary diaphragm 11011 to increase its throttling action on high pressure air conduit 120 which is connected to chamber 124a below fiexible diaphragm 125a and to chamber 130 above flexible diaphragm 131. A restriction 132 is provided in conduit 120 between its connection to chamber 12411 and its connection to cham-ber 130.

Diaphragms 125:1 and 131 are rigidly interconnected by a block 133 from which projects an arm 134 extending over the exhaust aperture 12911 in nozzle 132a of conduit 132 which latter is connected into shuttle valve chamber |66 as in FIG. l. Arm 134 is normally biased to close aperture 129a by spring 12611, the pressure in conduit 120 being equally oppositely effective on equal area diaphragms 125a and 131.

Should there be a gradual rise in the low air pressure in chamber 11211, as due to product accumulation partially blocking the lower end of sensing tube 55, such results in a proportionate displacement of primary diaphragm 110A to increase its throttling action on the open end of conduit 12() and there is a proportionate rise in the amplified sensing air pressure in conduit 120. Since this rise is gradual it has equal effect in opposed diaphragm chambers 12411 and 130 and so it does not affect the spring biased closure of aperture 12911.

However, when there is a sudden increase in the pressure in chamber 11211, as when the rising material in the container blocks the lower end of sensing tube 55, there is a resultant proportionate amplified rise in pressure in conduit 120. Due to restriction 132 this increased high air pressure is momentarily differentially applied to chambers 12411 and 130, with the higher pressure applied to diaphragm 12511 acting against spring 12611 to quickly lift arm 134 from aperture 12911 and this exhausts the shuttle valve chamber 66 to permit operation of the shuttle valve to assume the FIG. 3 position where it closes product fill valve 33.

The pressure in chamber 12411 and 130 eventually equalizes and spring 126a returns arm 134 to close aperture 129a but by that time the sensing tube 55 is usually lifted out of the filled receptacle.

FIGS. 5 and 6 illustrate a useful and practical physical embodiment of the system portion shown in FIG. 4, certain corresponding parts bearing numbers corresponding to FIG. 4. In this embodiment the amplified sensing air pressure conduit and the conduit connection 132 between shuttle valve chamber 66 and the nozzle 13211 appearas passages in a common support base 135.

The diaphragms 12511 and 130 are externally peripherally clamped in a housing structure 136 fixed to base by fasteners (not shown). The lower end of housing 136 is open at 137 'where it extends over the open end of conduit 120 and a suitable resilient seal 138 surrounds the opening. The interior of the housing is separated into a lower diaphragm chamber 12411 connected to conduit 120, and an upper diaphragm chamber 130.

The diaphragms are internally peripherally clamped upon the vertical stem 139 of a diaphragm biasing weight 1-41 disposed mainly in chamber 130. The inner end of arm 134 is apertured to pass stem 139 and spacer collars 142 and 143 extend between the arm and the respective diaphragms. The inner periphery of diaphragm 131 is clamped between collar 142 and an enlarged guide section 144 of stem 139. A cap 145 secured on the lower end of stem 139 as by a screw 146 clamps the inner periphery of diaphragm 12511 against collar 1-43 and axially secures the stem, arm, collars and diaphragm inner portions in tight assembly.

The upper guide end section of stem 139 is further enlarged at 147. As shown in FIG. 6 these guide sections of the stern are cylindrical for sliding up and down in the cylindrical bore 148 of chamber 130. A continuous longitudinal grooving indicated at 149` on both guide sections insures and positively provides a passage for unrestricted air communication throughout diaphragm chamber 130.

Chamber 124a is constantly connected to chamber 130 by a housing passage 150 formed by lateral bore 151, longitudinal bore 152 and lateral bore 153. This passage contains a fixed restriction 154, which corresponds to restriction 132 in conduit 120 in FIG. 4, and is here physically formed as an opening in that portion of diaphragm 12511 that extends across passage 150. If desired this restriction can be formed anywhere along passage 150.

In this embodiment the weight on stem 139 acts like spring 126r1, the amplified sensing air pressure acting equally on equal area diaphragms 125:1 and 131. A sudden rise in pressure in conduit 120 quickly displace the diaphragms and weight upward to uncover aperture 12911 and trigger the shuttle valve to stop product fill as it does in the other embodiments. The enlarged guide sections of the stern 139 insure rectilinear motion of arm 134.

The invention may be embodied in other specific forms 1without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects are illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. Automatic container filling apparatus comprising a product filling head nozzle adapted to be cyclically introduced into a container to be filled, withdrawn after filling and then introduced into a further container to be filled, means providing a fluid pressure control sensing passage that extends tothe lower end of said nozzle for operative association with the rising product level in the container being filled, means providing sensing air at a predetermined relatively low pressure level to said passage, a product supply conduit connected to said nozzle, a valve in said conduit, a pressure responsive operator connected to said valve, a fluid pressure actuating circuit connected to said operator, a reversible valve provided in said actuating circuit, pressure responsive means for controlling said actuating circuit to operate said reversible valve, control means for said pressure responsive means comprising a fiuid pressure control circuit having pressure sensitive means responsive to a sudden change in pressure in said passage, and compensating means in said control means for maintaining a threshold operating pressure in said control circuit regardless of gradual uncontrolled increases in said pressure level in said sensing passage during successive till cycles, for providing substantially uniform shut off of the product supply valve and thereby providing substantially uniform filling of successive containers.

2. The apparatus defined in claim '1, wherein said control means comprises a primary flexible diaphragm subject to the presssure of said passage and a secondary diaphragm connected to control the pressure in said control circuit, and said compensating means comprises means defining a variable volume chamber having a re stricted outlet interposed between said diaphragms.

3. The apparatus defined in claim 1, wherein said pressure responsive means includes a movable pressure responsive element and said control circuit pressure is applied to opposite sides of said element through a passage section that interconnects chambers associated with said respective sides and has a restriction between said sides, and means connecting said element to control operation of said control circuit.

4. The apparatus defined in claim 3, wherein said element comprises flexible diaphragm means with one of said chambers being connected to said control circuit and the other containing means biasing the diaphragm means in one direction.

5. The apparatus defined in claim 4, wherein said pressure responsive means comprises a casing wherein said chambers are vertically spaced by said diaphragm means, and said biasing means comprises a weight means disposed in the upper chamber.

6. The apparatus defined in claim 4, wherein said control circuit includes a discharge nozzle and said nozzle is normally closed by a member on the biased diaphragm means.

7. The apparatus defined in claim 3, wherein said control means comprises a primary fiexible diaphragm subject at one side to the pressure of said sensing passage and at its other side to pressure in said control circuit.

8. Automatic container filling apparatus comprising a product filling head having a discharge nozzle, means whereby said nozzle is cyclically introduced into a container to be filled, `withdrawn after filling and then introduced into a further container to be filled, means defining a fluid pressure sensing passage extending to the lower end of the nozzle for operative association with the rising product level in the container being filled, means providing air at a predetermined relatively low sensing pressure level to said passage, means defining a product fill circuit connected to said nozzle, valve means in said fill circuit, a pressure responsive operator connected to said valve means, a relatively high fiuid pressure actuating circuit connected to said operator, means for automatically activating said actuating circuit to actfuate said operator to close said valve means when a container has been filled to a predetermined degree comprising pressure sensitive means responsive to a sudden appreciable increase in pressure in said passage such as may be caused by the rising product in a container blocking the lower end of said passage, and compensating means for automatically preventing small uncontrolled increases in said low pressure level in said sensing passage, such as may be caused by accumulation of product within the passage to gradually restrict the passage during successive fill cycles, from causing premature shut off of said vvalve means by said actuating circuit for providing substantially uniform shut 10 ofi? of said product fill valve means during the successive fill cycles and thereby providing substantially uniform filling of successive containers.

9. The apparatus defined in claim 8, wherein said compensating means maintains a substantially constant threshold value for the pressure in said actuating circuit regardless of said pressure increase in said passage.

10. The apparatus defined in claim 8, wherein said pressure sensitive means comprises a control device wherein said actuating circuit pressure is applied directly to one side of a first fiexible diaphragm, and the pressure of said passage is operatively applied to the other side of said diaphragm, and said compensating means is applied to control the pressure level in said actuating circuit.

11. The apparatus defined in claim 10, wherein said compensating means comprising a second diaphragm in said control device defining a variable volume chamber between said diaphragms, said chamber having a restricted vent whereby said gradual increases in low sensing pressure level in said passage result in corresponding volume changes in said chamber without affecting said activating circuit pressure, and an abrupt change in said passage pressure will produce a sudden force transmitted through said changer to displace said first diaphrgam to activate said actuating circuit.

12. The apparatus defined in claim 10, wherein the operator for said valve means has a movable pressure responsive element and said actuating circuit pressure is applied to opposite sides of said element by a conduit having a restriction in the portion between said opposite sides.

13. The apparatus defined in claim 8, wherein said compensating means provides shut off of said product fill valve means within a uniform predetermined time after a sudden change in pressure starts in said passage regardless of the then effective value of said actuating circuit pressure.

14. In a container filling machine, in combination, a filling head having a liquid supply inlet and an outlet nozzle to be extended into the open mouth of a container to be filled, a liquid control valve in said filling head, air conducting means comprising a tube terminating in an outlet at a predetermined level within the container and extending a substantial distance below the end of said outlet nozzle during the filling operation, said air conducting means being arranged to discharge air continuously ata relatively low pressure into the container, means for supplying sensing air at a predetermined low pressure level to said air conducting means during container filling, said low pressure outlet being blocked by the liquid when it reaches said predetermined level to create a back pressure in the air conducting means, and pneumatically operated control means responsive to said back pressure for operating said valve to discontinue the fiow of liquid into the container, said pneumatically operated control means including a high pressure air circuit having an outlet through which air may escape to the atmosphere during the filling operation, and a diaphragm valve associated with said low pressure air conducting means and arranged to be operated by said back pressure to close said high pressure outlet whereby to render the control means operative to effect closing of the valve when the liquid reaches said predetermined level, and compensating means operatively associated with said control means for automatically preventing an uncontrolled increase in said low pressure level, such as may be caused by product accumulation restricting the lower end of said tube, from causing premature closing of said high pressure outlet during filling of a container.

1S. In the apparatus defined in claim 14, said compensating means comprising means maintaining a predetermined pressure in said high pressure air circuit regardless of the pressure, level in said air conducting means.

16. In the apparatus defined in claim 14, said com- 1 1 pensatng means being incorporated in said high pressure air circuit and being effective to proportionately increase the threshold level of operating pressure in said high pressure air circuit in proportion to an increase in said predetermined 10W pressure level in said air c011- 5 ducting means.

12 References Cited UNITED STATES PATENTS 3,182,691 5/1965 Vergobbi et a1 141-41 X 3,207,189 9/1965 Vergobbi 141-41 X HOUSTON S. BELL, JR., Primary Examiner U. S. C1. X.R.

Patent No.

Inventor(s) Column 2,

tion

Column 5,

Column 5,

Column 6,

Column 6,

Column 7,

Column 8,

Column 8,

Column 8,

Column 8,

ALFRED MOCRE Dated September 8, 1970 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column l, line 25, after "pressure" insert -rise--.

Column 2, line 34, cancel "wherein automatic compensation is provided for insuring".

line 35, after "effect" insert --automatic compensafor insuring--.

line 47,

line 60,

line 26,

line 42,

line ll,

line ll,

line 33,

line 58,

change change change change change change insert a comma after change illustrative--.

line 704,

"are illustrative" to (line 6 of Claim l) change "tothe to Signed and sealed this 6th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER, JR.

Attestng F ORM PO-IOSO (IO-69) Officer USCOMM-DC 60376-P69 a u.s, GGVERNMMT PRINTING ofncf less o-us-su 

